Sheet advancer



Oct. 31, 1967 c. L. LARSON 3,350,090

SHEET ADVANCER Filed Sept. 14, 1965 2 Sheets-Sheet 1 I, 0.0 -'\-J Q Charles LLar'son l i? INVENTOR n 744A 4m HHgs.

Oct. 31, 1967 c. LARSON 3,350,090

SHEET ADVANCER Filed Sept. 14, 1965 2 Sheets-Sheet 2 C har'les L.Larson INVENTOR.

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United States Patent 3,350,090 SHEET ADVANCER Charles L. Larson, Grants Pass, Oreg., assignor to Jeddeloh Bros. Sweed Mills, Inc., Gold Hill, Oreg., a corporation of Oregon Filed Sept. 14, 1965, Ser. No. 487,246 4 Claims. (Cl. 271-43) ABSTRACT OF THE DISCLOSURE A sheet advancer including an elevatable support for a stack of sheets, and a fence disposed to one side of a stack on such support. A carriage movable along a track is mounted over the stack of sheets, and a pair of elongated, substantially parallel arms journaled adjacent one set of their ends on the carriage are moved aong the path of the carriage with movement of the carriage. The arms are biased whereby their nonpivoted ends are offset laterally to one side of their pivoted ends, and when the carriage is moved along the track, shoes on the arms engage the top sheet in the stack and urge the sheet both laterally against the fence and in a direction generally paralleling the path or movement of the carriage on the track. The arms are flexible and resilient, whereby a stack may be moved up under the arms with the arms giving. The arms are linked together whereby they are maintained parallel at all times.

This invention relates to apparatus for advancing successive sheets, such as panels and the like, from a stack of such sheets. More particularly, the invention concerns apparatus for removing at intervals a layer of sheets from a stack, the layer in the usual instance comprising a single sheet thickness, whereby the sheet or sheets contained in the layer may be further processed. Exemplary of apparatus of this description is mechanism utilized to advance panels from a stack of panels for sanding, the mechanism being operable to shift panels one at a time from the top of a stack into the feeding system of a sander located to one side of such stack.

The invention will be described hereinbelow in connection with the feeding of panels into a sander, although it should be understood that this is for illustrative purposes only, and the apparatus contemplated has other uses than the specific one described.

A general object of the invention is to provide improved means for advancing sheets from a stack, which performs not only the function of shifting a sheet or sheets laterally of the stack, but also a positioning function, wherein a sheet on leaving the stack becomes properly aligned with structure provided to receive the sheet.

Another general object of the invention is to provide a sheet advancer, which will produce proper positioning in sheets advanced to one side of a stack, irrespective of differences in the position of respective sheets in the stack immediately prior to being advanced.

Yet another object is to provide sheet-advancing mechanism which can accommodate changes in the level of the top of the stack being processed.

Another object is to provide sheet-advancing mechanism which is rapid and reliable in operation, yet relatively simple in construction.

The advancing mechanism of the invention features at least one arm, which immediately prior to advancing a sheet from off the top of a stack assumes a diagonal position relative to the primary direction of the path in which the sheet will move. The arm adjacent one of its ends is mounted for swinging movement, and the other or free end of the arm includes sheet-engaging means adapted to pass over what is the rear edge of a sheet with the sheet moved from the stack and engage said edge. When the ap- Patented Oct. 31, 1967 paratus is actuated, the arm moves a sheet and forces are exerted on the sheet by the arm which direct the sheet off to one side of the stack, and also urge the sheet in a direction extending laterally of the sheets path from the stack whereby the sheet is moved into contact with a fence or guide producing proper alignment of the sheet relative to the structure receiving it. Sheets on leaving the stack thus always have a properly aligned position with respect to the mechanisms receiving the sheets, even though there be differences in the starting positions of successive sheets. The apparatus readily adapts itself to handling sheets of different sizes and thicknesses, with little or no adjustments required therein.

In a preferred embodiment of the invention, a pair of arms are employed, which are generally parallel to each other, and both of which extend generally diagonally of the path of a sheet from the top of the stack, as just described. With such arms, a sheet is engaged at points spaced along its rear edge, minimizing any tendency of the sheet to become skewed in moving from a stack.

The apparatus contemplated is adapted to feed sheets rapidly one after another from the top of a stack. The apparatus thus includes a platform or other means for supporting a stack which is elevated under the stack to maintain the top of the stack adjacent the arms described. Preferably the arms include flexible portions, whereby the ends having the sheet-engaging means are yieldable upwardly and are spring-biased downwardly. As a consequence, proper operation of the arms is possible regardless of differences in the level at the top of the stack.

These and other objects and advantages will become more fully apparent as the following description is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a top plan view of sheet-advancing apparatus according to one embodiment of the invention, illustrating portions of the top of a stack of sheets, and advancing arms With shoes mounted on free ends of the arms for engaging the rear edges of sheets to enable shifting of the sheets laterally of the stack;

FIG. 2 is a side elevation of portions of the sheet-advancing mechanism illustrated in FIG. 1;

FIG. 3 is an enlarged view of an end of one of the advancing arms, showing a shoe mounted at the base thereof; and

FIG. 4 is a side elevation of the arm and shoe illustrated in FIG. 3.

Referring now to the drawings, the advancing apparatus shown comprises a frame, portions of which are generally indicated at 10. Included within frame 10 and supported by suitable framework (not shown) above the ground, are substantially parallel top frame members 14 and 16. Joined at their ends to frame member 14 are longitudinals 18 and 20. Cross pieces 22, 24 secured to the longitudinals, by way of brackets 26, extend between the longitudinals.

A stack of panels, from which panels are to be advanced one at a time from off the top of the stack, is shown at 28. The frame structure just described, including frame members 14, 16, the longitudinals and'cross pieces 22, 24, is supported at an elevation which is somewhat above the top of this stack of panels.

Generally paralleling longitudinals 18 and 20' and extending between cross pieces 22, 24 is a guide rod or bar 30. Fasteners 32 (see FIG. 2) connect the ends of the guide rod to cross pieces 22, 24, at locations substantially midway between the ends of these cross pieces. Slidably supported on guide rod 30 is a tube or sleeve 34, forming part of a carriage or mounting 36, which is movable to and fro along the length of the guide rod. The guide rod thus functions as a track means for the carriage or mounting accommodating movement of the carriage along a staright path, between the position illustrated in FIGS. 1 and 2, and a position wherein the right end of the sleeve 34 strikes cross piece 24.

Movement of the carriage to and fro on the bar is produced by the actuation of a double acting ram designated generally at 38. This ram includes a cylinder 40 fastened at one end to a bracket 42, which bracket is secured to frame member 14. Cylinder 40 is secured at its other end to a bracket 44 which is fastened to frame member 16. Rod 46 of the ram joins with a clevice 48 which is connected by pin 50 to a post 52 extending up from and joined at its base to sleeve 34. It should be obvious from this description that on extension of ram 38, sleeve 34 shifts to the right on the guide rod, and on contraction of the ram the sleeve is returned to the position shown.

Carried at the base of the sleeve and also part of carriage 36 is a plate 54. The plate is joined to the sleeve as by welding. Projecting out to either side of the plate at the end shown to the left in FIGS. 1 and 2 are supporting brackets 56, 58, which are shown secured to the plate through fasteners 60.

Referring to FIG. 1, the path of carriage 36, on actuation of the ram, coincides with the longitudinal axis of guide rod 46. To advance a panel from off the stack of panels 28, the carriage is shifted to the right in FIG. 1, which movement results in lateral shifting to the right of the top panel in the stack. Interposed between the carriage and the top panel in the stack are a pair of advancing arms 62, 64, operable to produce such movement in the panel on shifting of the carriage.

Each of these advancing arms is journaled to one of the supporting brackets 56, 58, as by pivot connection 66 shown for arm 62. The pivot connections for the two arms are aligned in a direction extending normal to the path of movement of the carriage, viewing a plan view of the carriage as in FIG. 1. Mounted on the underside of the two advancing arms, at points which for the two arms are spaced at equal distances from the pivot connections for the arms, are sheet edge engaging means or shoes 68. In the embodiment illustrated each shoe is joined to an arm by a pair of fasteners 70, 72 (see FIGS. 3 and 4).

Pivot connections 66 enable the two arms to swing from the positions shown for the arms in solid outline in FIG. 1 (which are positions where the ends of the arms carrying the shoes are offset in the path of movement of the carriage laterally to one side of the arm ends which are pivotally connected to the supporting brackets) to the posi tions shown in dashed outline, where the arms generally parallel the path of movement of the carriage. Maintaining the arms parallel in their various positions is a linking rod 74, joined to the two arms adjacent their ends by fasteners 70.

As best seen in FIG. I, mounted on supporting bracket 58 and extending downwardly therefrom is a stop 76. The stop 'limits lateral swinging of arm 64 and the degree of offset of the free end of the arm. Since the two arms are connected together, this also limits the offset of the free end of arm 62. Biasing the arms, whereby they are constantly urged to the laterally offset position described is a coil spring 78, connected to arm 62 at 80 and bracket 58 at 82.

Pivot connections 66 mount the arms whereby they are pivotable about generally vertical axes. The ends of the arms mounting shoes 68 are resiliently yieldable upwardly, or in a direction generally paralleling the pivot axes of the arms, by reason of the fact that each arm comprises a length of spring steel, shown at 84 for arm 62. The resiliency provided in the free ends of the advancing arms is important in promoting flexibility and rapidity in operation, as will be hereinafter described.

As earlier discussed, the advancing mechanism may be employed in the feeding of panels such as plywood panels to a sanding machine. Shown in FIG. 1 at 85 is a fence or guide which is provided to align one margin of a panel leaving the stack with the usual feed rolls or other feed means present in the sanding machine (not shown).

Completing the description of the apparatus, stack of panels 28 is supported underneath the carriage and arms on a platform 86, which is elevatable upwardly by actuation of suitable elevating mechanism, exemplified by the scissor lift mechanism partially shown at 88. During operation of the apparatus, the lift mechanism is actuated after the removal of a panel to shift the top of the stack upwardly genera-11y to the level occupied by the top of the stack prior to removal of the panel.

Explaining now the operation of the apparatus, a stack of panels is first placed on platform 86 with the platform in a lowered position. The exact position of the stack on the platform is not critical, however, the stack should be located somewhat to one side of fence to enable the top, of the stack when the stack is raised to pass to one side of the fence. The advancing arms on movement of the carriage are utilized to produce both movement of a panel in a direction generally corresponding to the path of movement of the carriage, and lateral movement of the panel toward the fence, whereby on the panel entering the sander the same occupies a proper feeding position.

More specifically, to advance a panel from the stack, the carriage and the arms are first shifted to the left in FIGS. 1 and 2 :by contraction of ram 38, which enables the shoes at the free ends of the advancing arms to drop downwardly behind the rear edge of the top panel in the stack. Spring 78 functions to urge the arms to their offset position. Ram 38 is then extended, and with such actuation of the ram, the carriage shifts to the right in FIGS. 1 and 2, to bring the two shoes into engagement with the edge of the top panel in the stack. On further movement of the carriage, the shoes slide the top panel off the stack, imparting to the panel because of the diagonal position of the advancing arms a force which includes a component generally paralleling the path of movement of the carriage and a component extending generally normal to fence 85 described. As a consequence, on being shifted to the right of the stack the panel also moves toward the fence. On engaging the fence and on further extension of the ram, movement of the panel is confined to a direction generally paralleling the axis of the ram (or in a direction paralleling the fence). Thus, each panel as the same is advanced off the top of the stack prior to reaching the feeder is positioned against the fence 85.

Ordinarily the advancing arms are not employed to move the panel completely off the stack of panels, and on full extension of ram 38, the shoes described are still located over the top of the stack. The feed means of the sander completes the removal of the panel from the top of the stack. During this time the arms may be returned to the left in FIGS. 1 and 2, and at the same time that the arms are being returned, the stack of panels may be elevated to place the panel now at the top of the stack at proper elevation for advancement into the sander. Because of the flexible nature of the arm, this upward movement of the stack is accommodated with the shoes moving over the top panel in the stack. On clearing the left edge of the stack in FIG. 1, the shoes drop downwardly to be in proper position to engage the rear edge of the top panel.

It should be obvious from the above that a relatively simple mechanism is contemplated which is nevertheless entirely practical and reliable in operation. The apparatus does not require that the stack be exactly positioned for proper advancement of the top panels therefrom, nor does the apparatus require that the elevation of the top panel in the stack of panels be exactly the same for each panel. The apparatus can accommodate panels of different sizes without major adjustment therein. The only power-op erated mechanism in the embodiment of the invention specifically disclosed comprises the scissor lift mechanism and ram 38 which is extended and contracted to move the carriage.

While a specific embodiment of the invention has been described, it should be obvious that modifications and variations are possible without departing from the invention. It is desired to cover all such organizations of the invention as would be apparent to one skilled in the art, and that come within the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. Apparatus for advancing sheets comprising a carriage,

substantially horizontally disposed track means mounting the carriage for movement to and fro in a defined path,

power-operated means connected to said carriage for 2. The apparatus of claim 1 wherein biasing mechanism is included operatively connected to the arms urging their said opposite set of ends to a position in said.

path which is oflFset laterally to one side of said one set of ends of the arms, and a sheet guide is included paralleling the track means to the opposite side of said one set of ends of the arms.

3. The apparatus of claim 2 wherein the arms are flexible and resilient, whereby their said opposite set of ends are yieldable in a direction generally paralleling the pivot axes of the arms.

4. The apparatus of claim 3 wherein said arms are linked together at a point spaced from the pivot axes for the arms, for movement conjointly with each other. I

moving the carriage in its said path, 15 a pair of elongated, substantially parallel arms, jour- References Cited naled adjacent one Set Of the ends to said carriage, for pivotal movement about upright axes, the pivot axes for said arm being substantially aligned in a 2,355,873 8/1944 Lafallle 271-54 direction extending normal to said path of move- 20 2,960,805 11/1960 Herman 271 43 X ment for the carriage, and

means on the arms for engaging the edge of a sheet, said means for the two arms being spaced at equal distances from the pivot axes for the arms.

M. HENSON WOOD, JR., Primary Examiner. R. A. SCHACHER, Examiner. 

1. APPARATUS FOR ADVANCING SHEETS COMPRISING A CARRIAGE, SUBSTANTIALLY HORIZONTALLY DISPOSED TRACK MEANS MOUNTING THE CARRIAGE FOR MOVEMENT TO AND FRO IN A DEFINED PATH, POWER-OPERATED MEANS CONNECTED TO SAID CARRIAGE FOR MOVING THE CARRIAGE IN ITS SAID PATH, A PAIR OF ELONGATED, SUBSTANTIALLY PARALLEL ARMS, JOURNALED ADJACENT ONE SET OF THE ENDS TO SAID CARRIAGE, FOR PIVOTAL MOVEMENT ABOUT UPRIGHT AXES, THE PIVOT AXES FOR SAID ARM BEING SUBSTANTIALLY ALIGNED IN A DIRECTION EXTENDING NORMAL TO SAID PATH OF MOVEMENT FOR THE CARRIAGE, AND 